1. Field of the Invention
This invention relates to film-forming polymerizable resins which can be cured through pendant acrylic radicals by exposure to ultraviolet radiation.
2. Description of the Prior Art
Utilization of ultraviolet radiation as an energy source for curing resins requires conversion of light energy into chemical energy. The conversion is usually accomplished by adding a photoinitiator or photosensitizer which absorbs light energy and creates reactive initiators for free radical polymerization of the resin. Photoinitiators convert light into chemical energy by direct formation of free radicals as in benzoin ethers or by interaction with another substance which donates a hydrogen atom to the photoactivated species and in doing so generates a free radical as in benzophenone reacting with tertiary hydroxyl amine. Most photoinitiators have one or more of the following undesirable characteristics:
high toxicity, PA1 poor solubility, PA1 high cost, PA1 poor stability. PA1 (a) a monoepoxide, diepoxide or mixture thereof; PA1 (b) an ethylenically unsaturated monocarboxylic acid such as acrylic acid or methacrylic acid or an ethylenically unsaturated dicarboxylic acid or anhydride thereof such as maleic acid or anhydride; PA1 (c) BTDA.